When selecting testing for a suspected failure, what should be considered?

• A. Choose tests at random
• B. Tests that match the suspected failure mechanism and acknowledge limitations
• C. Tests based on availability
• D. Tests that are quickest

Answer: (B)

When you’re investigating a suspected failure, the key idea is to choose tests that directly probe the suspected failure mechanism and to be clear about what the test can and cannot reveal. If you think a problem stems from a bond or adhesion issue, you’d select tests that measure bond strength or delamination under conditions that mimic service—considering factors like temperature, moisture, aging, and substrate preparation. This targeted approach helps you gather evidence that supports or refutes the proposed mechanism rather than collecting data that may be irrelevant or misleading.

It’s also essential to recognize test limitations. No single test captures every variable of a complex system, and results can be influenced by sample representativeness, environmental conditions, measurement sensitivity, and the specific test method used. Interpreting results in the context of these limitations—and, when possible, using multiple tests or field observations to corroborate findings—leads to a more accurate understanding of the failure.

Choosing tests at random, based on availability, or aiming for the quickest result tends to miss the actual failure mode or overlook important contributing factors, which can lead to incorrect conclusions.